Impeller for dishwashing machines



, INVEN TOR. fi/memo 6 DAV/l5 BY A 77'0P/YE) Sept. 11, 1951 H. G. DAVISIMPEILLER FOR DISHWASHING MACHINES Filed May 2, 1949 Patented Sept. 11,1951 UNITED STATES PATENT OFFICE IMPELLER FOR DISHWASHING MACHINESHarold G. Davis, Denver, 0010.

Application May 2, 1949, Serial No. 90,978

2 Claims. 1

This invention relates to an impeller for dishwashing machines of thetype in which an impeller is placed in the bottom of a dish-containingtank for the purpose of throwing the water upwardly through the dishes.It is more particularly designed as an improvement over the impellershown in applicants Patent No. 1,934,970 and i designed for use in amachine of the type illustrated in applicants Patent No. 2,047,177.

The principal object of the invention is to provide a construction inwhich the stream of water will be thrown upwardly at an angle to thevertical and this stream will be continuously rotated about the verticalaxis so as to strike the dishes at an infinite number of differentangles so as to efficiently cleanse the same.

Other objects are: to provide highly efilcient means for guiding thewater thrown by the impeller which will operate efliciently at a lowlevel of water in the tank; to provide an efiicient oiling device forthe impeller which will prevent the oil from being forced from thebearings under the influence of heat; to provide highly eflicientbearing sealing means which will prevent the entry of water into thebearings; and to provide an effective brake construction by means ofwhich the speed of gyration can be pre-set at any desired speed.

Other objects and advantages reside in the detailv construction of theinvention, which is designed for simplicity, economy, and efficiency.These will become more apparent from the following description.

In the following detailed description of the invention, reference is hadto the accompanying drawing which forms a part hereof. Like numeralsrefer to like parts in all views of the drawing and throughout thedescription.

In the drawing:

Fig. 1 is a plan view of the improved. impeller.

-Fig. 2 is a vertical section therethrough taken on the line 2-2,Fig. 1. In this view the impeller blades have not been cut by thesection for the purpose of clarity of illustration.

Fig. 3 is a detail cross-section taken on the line 3 -3, Fig. 2.

Fig. 4 is a similar cross-section taken on the line 44, Fig. 2.

In the drawing, the related parts of the dishwasher have been omittedsince this application pertains only to the impeller portion thereof.However, the position of the bottom of a dishwashing tank is indicatedat In and the position of the top of a fan housing is indicated at ll.

The entire structure is supported in a cylindrical outer housing l2having a top peripheral flange IS. The flange rests upon a suitablesealing gasket 14 which seals it to the bottom ID of the tank. A similarsealing gasket I5 is placed between the two members In and II and theentire structure is clamped to the members l9 and H by means of a clampnut Hi. The bottom ll] of the outer housing is closed by a threadedbottom cap H.

An inner housing [8 is rotatably mounted within the outer housing l2 andextends above the top thereof. The upper extremity of the inner housingterminates in a bearing cup I9, the axis of which is at an acute angleto the axis of the inner housing l8. This angle may be any suitabledegree, it having been found that an angle of 17 is the mostsatisfactory. The cup i9 is enclosed by means of a top cap 20 threadedthereon.

A hollow, cup-like bearing member 2| is threaded on the lower extremityof the inner housing 58 and is rotatably mounted within the outerhousing 42 so as to rotatably support the latter and maintain itaccurately on its axis. The interior of the hollow bearing member 2| issealed from the interior of the tank b means of an inverted sealing cup22 which is constantly urged against the top of the outer housing 12 bymeans of a compression spring 23 which rests on the bottom of thebearing member 2|.

It can be seen that the above construction allows the inner housin torotate freely about its axis, the rotation being snubbed by the frictionbetween the cup 22 and the top of the housing 12. This snubbing actioncan be pre-set by choosing the spring 23 of the proper strength.

A trunnion bearing 24 is rotatabl mounted in the cup I9 and carries ahollow, axially-extending spindle 25 which extends through and above thecap 20. The bearing 24 is sealed from the interior of the tank by meansof an inverted sealing cup 26 and sealing spring 21, similarly to thepreviously described sealing means. The cup 26 is constantly urgedagainst the cap 20 by means of the action of the spring 27.

A hollow impeller hub 28 is wedged on the spindle 25, the latter beingtapered to receive it. The skirt of the hub 28 extends downwardly aboutthe cup [9. Two oppositely-projecting, tangentially-mounted, curvedimpeller blades 29 project oppositely outward from the skirt of the hub23. These blades are so curved as to impart a scooping action on thewater to throw it upwardly about the axis of the spindle 25 in a more orless'confined spiral stream.

The hub 28 is held in place on the spindle 25 by means of an oil cup 30threaded onto the upper extremity of the latter. The interior of the cupis open to the hollow interior of the spindle 25. The cup is closed bymeans of a threaded cup cap 3| provided with a suitable sealing gasket32 which forms an air tight seal on the cup 30.

It has been found in prior impeller mountings that when the latterbecome heated through the action of the hot water and the friction ofrotation, the oil therein will be expanded and forced through thebearings into the tank. In the improved construction, any expansion inthe oil is absorbed in compressing the entrapped air in the top of theoil cup 30 so that the oil will not be forced from the bearings.

The impeller is driven through the medium of a drive shaft 33, the lowerextremity of which projects below the bottom cap I1. The lower extremityis suitably threaded, as shownat 34, to provide a connection for anysuitable driving element. A sealing skirt 35 is formed on and surroundsthe shaft 33 immediately above the cap IT. This skirt contains a sealingcup 36 against which :a spring 31 acts to seal the housing above theshaft 33. The spring 3'! acts to constantly urgethe cup 36 against thecap I? to prevent water or other liquid from entering the outer housingl2.

A section of flexible shafting 38 is fixedly secured in the shaft 33 inany desired manner, such as by soldering it in a receiving sockettherein.

The upper extremity of the shaft 33 contains a conical concavity inwhich the flexible shaft 38 may move. The upper extremity of this shaft38 terminates in a terminal member 39 which rests in the hollow spindle35. The terminal member is notched and a key member 40 in the spindleextends across this notch to provide a driving connection for theimpeller which will allow freedom for axial movement of. the terminalmember 39. I

The bearing member 2| and the inner housing 18 are supported on acombination thrust and bearing member 41 which is rotatable within theouter'housing I2. The thrust member 4! has the proper thickness tosupport the inner housing 18 at the desired heighth when the cap ll hasbeen screwed in place to its final position. It is this bearing member4| which supports the entire rotating assembly at the proper heighth inthe tank.

The inner housing [8 is rotated through the whirling action of the bentflexible shaft 38, and this action is retarded by the friction betweenthe elements 22 and 13 to the desired gyration speed.

The speed of gyration is still further controlled by means of a flatvane plate '44 which is attached to the inner housing l8 by means ofsuitable screws 45. The vane plate 44 acts as a drag through the .waterin the tank to retard the gym-- tion speed of the inclined impeller. Thecurved cross-section of the blades 29 tends to throw the water upward inan inclined stream concentric with the inclined axis of the impeller. Ithas been found desirable to divert a portion of this stream rearwardlyfrom the direction of rotation to increase the cleansing action. This isaccomplished by means of an arcuate inclined scoop 42 which is supportedover the lowermost side of the path of the blades 29 upon a scoop arm 43which is formed on and extends from the vane plate 44. The scoop acts todivert a strong stream of water rearwardly from the direction ofrotation and against the dishes to be washed.

It will be noted that the arm 43 is arched as shown at 46 to allow it topass the projecting impeller mechanism and that the scoop is over thelowest position of the blades so that it will receive water even thoughthe water level in the tank be below the middle of the impeller.

While a specific form of the improvement has been described andillustrated herein, it is desired to be understood that the same may bevaried, within the scope of the appended claims, without departing fromthe spirit of the inven-- tion.

Having thus described the invention, what is claimed and desired securedby Letters Patent is:

1. In a dishwashing machine of the type having a tank, means foragitating water in said tank comprising: a rotatable shaft housingextending vertically through the bottom of said tank; a bearing cupformed on the top of said housing and inclined to one side at an acuteangle to the axis of said housing; an impeller mounted to rotate aboutsaid cup co-axially therewith; means for rotating said impeller; and anarcuate, inclined scoop mounted on said shaft housing and positionedover said impeller at one side of the axis thereof, the incline of saidscoop being positioned to direct water rearwardly from the direction ofrotation of said impeller.

2. In a dishwashing machine of the type having a tank, means foragitating water in said tank comprising: a rotatable shaft housingextending vertically through the bottom of said tank; a bearing cupformed on the top of said housing and inclined to one side at an acuteangle to the axis of said housing; an impeller mounted to. rotate aboutsaid cup co-axially therewith; means for rotating said impeller; and anarouate, inclined scoop mounted on said shaft housing and positionedover said impeller at one side of the axis thereof, the incline of saidscoop being positioned to direct water rearwardly from the direction ofrotation of said impeller, said scoop being positioned over thelowermost side of said impeller; and a supporting arm secured to saidshaft housing and extending radially outward beneath the high side ofsaid impeller, thence upward and over said impeller to a connection withsaid scoopfor supporting the latter.

HAROLD G. DAVIS.

REFERENCES CITED I The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 911,412 Lang Feb. 2, 19091,934,970 Davis Nov. 14, 1933 2,398,733 Wenzel Apr. 16, 1946

